Improvement in ratchet-drills



T. J. LAVERY. Y Improvement in Ratchet-Drills. No. 130,645 Patented Aug.20,1872.

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surface. transferring the point of revolving contact UNITED STATESTHOMAS J. LAvERY, or BOSTON, iuAssAoaUsnrrS.

IMPROVEMENT iN RATCHET'DRILLS.

Specification forming part of Letters Patent No. 'B3-0,645, dated August1872.

Specification describing certain new and useful Improvements inRatchet-Drills, invented by THOMAS J. LAvEnY, of Boston, in the countyof Suffolk and State of Massachusetts.

In the use of ratchet-drills, as heretofore constructed, it has alwaysbeen necessary to carry with the drill, to the placel of use, a shortpiece of iron or steel plate, with a countersunk recess formed therein,to be employed as a rest for the upper end of the drill-stock, theconical point thereon being placed in said countersink, and revolving'therein when the drill is in use. Said rest-plate being made v separatefrom the drill, and having no connection therewith, except when in use,was always a source of trouble, from the fact that it required two mento set a drill in position for use 5 the plate was liable to slip whenplaced on an inclined surfaceand throw the drill out of line, and oftenfalling into out-ofthe-way or inaccessible places when using the drillon board ship or in other difficult places. Another Source of trouble,arising from the construction and manner of using the old ratchet-drillswas the impossibility of properly lubricating the bearing-point in theconntersunk rest-plate, which took the whole thrust of the drill. Toovercome these objections is the object of my invention; and itconsists, rst, in attaching the rest-plate to the drill-stock in such amanner that it is always with and forms a part of the same, and

so that it may accommodate itself to the surface against which i-t isdesirable to have it bear. It consists, in the, second place, in makingthe outer surface of the rest-plate serrated or roughened,by raisingteeth thereon somewhat like a coarse rasp, to prevent it from slippingwhenplaced on an inclined It consists, in the third place, in

from the rest-plate to a point within the casing of the drill-stock,where the bearing-surfaces can be well lubricated, as will be furtherdescribed.

Figure 1 of the drawing is an elevation of an ordinary ratchet-drillwith my improvement attached thereto, a portion of the handle beingbroken away, and the rest-plate being shown slightly inclined. Fig. V2iS a vertical section of the saine. Fig. 3 is a plan of the rest-plate;and Fig. A is a modification, representing the mode of construction fornew drills, Figs. 1 and 2 showing the improvement as constructed to beapplied to drills already in use.

A is the ratchet-lever; B, the ratchet-wheel; C, a spring-pawl; D, thedrill-socket; E, the feed-screw 5 F, the shank containing the nut; G,the sleeve inclosing the feedscrew, and by which it is operated; and H,the steel point, which, in working the drills now in use, is placedagainst the rest-plate, and revolves thereon; all of the above-mentionedparts making up a well-known drill now in commonr use, the upper end ofthe sleeve G being slightly altered in order to apply my improvement. Iis my improved rest-plate, having its upper surface roughened, as'shownin Figs. 2and 3, and attached to the spindle J by Y a ball-andsocketjoint, as shown. The spindle J is tted to the casing K in such a mannerthat it cannot be accidentally removed therefrom, and has its lower endslightly convex. A washer, L, having its upper surface convex, and itslower surface cupped ont so as to t closely onto the point H of the olddrill-stock, is placed in the casin g K in such a position that thespindle J will rest there on, and, as there will be much less frictionbetween the two convex surfaces of the washer L and spindle J thanbetween the ball at the upper end of the spindle J and its socket in therest-plate, or between the under side of said washer and the conicalpoint H, it is evident that the point of revolving contact will bebetween said convex surfaces, instead of between the upper end oftlie's'pindle J and the rest-plate I, and,`as said convexbearing-Surfaces are inclosed in the casing, they can be keptwelllubricated, said casing beingI provided with an oil-chamber, a, for thepurpose. The casing K, as shown in Figs. l and 2, is

. made separate from the drill` stock proper,

and screwed thereto, so as to become virtually a part of thedrill-stock; this being done in order to apply my improvement to drillsalready in use but in the manufacture of newv Adrills with myimprovement I propose to make the casing K and the sleeve in one piece;and also the feed-screw E and washer L in cn piece, as shown in Fig. 4,thereby reducing kby Letters Patent of the United States, is-

l. In combination with a ratchet drill,7 commonly so called, arranged tobe operated by means of a lever and pawl, and provided with afeed-screw,the rest-plate I, permanently attached thereto by means of aballandsocket joint, or its equivalent, so as to operate substantiallyas described, for the purpose specified.

2. rEhe arrangement in the casing K of a ratchet-drill stock, oftheconvex-bearing surfaces J and L to receive the thrust of thedrill, andupon which the drill-stock revolves, substantiallyas described,for thepurpose specified.

Executed at Boston this 16th day of April,

y THOMAS J. LAVERY.

Witnesses i N. C. LOMBARD,

DAVID T. PRAY.

